834
FXUS65 KBYZ 211833
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
1233 PM MDT TUE JUL 21 2026
KEY MESSAGES
- SCATTERED THUNDERSTORMS MAINLY SOUTHERN MOUNTAINS LATE THIS
AFTERNOON & EVENING, THEN MOST OF AREA WEDNESDAY & THURSDAY.
STORMS COULD PRODUCE VERY HEAVY RAINFALL AND GUSTY WINDS.
- THUNDERSTORMS HAVE THE POTENTIAL TO CREATE VERY HEAVY RAINFALL
OVER BURN SCARS WEDNESDAY EVENING. PLAN AHEAD IF RECREATING NEAR
ANY BURN SCARS.
- THIS WEEKEND INTO EARLY NEXT WEEK IS LOOKING HOTTER & DRIER; A
RETURN OF TRIPLE DIGIT HEAT EXPECTED (STARTING FRIDAY). FIRE
DANGER MAY INCREASE.
DISCUSSION
THROUGH NEXT TUESDAY...
BAND OF VERY ELEVATED WARM FRONTAL LIGHT SHOWERS CONTINUES TO
CLIP FALLON COUNTY, BUT THIS ACTIVITY SHOULD EXIT OUR AREA SOON.
MESOANALYSIS SHOWS PWATS HAVE RISEN TO 1-1.2" AND THIS WILL LEAD
TO CONVECTION DEVELOPING OVER THE SOUTHERN MOUNTAINS BY AROUND
21Z. EASTERLY WINDS AND "COOLER" TEMPS WILL KEEP INSTABILITY
CAPPED ACROSS LOWER ELEVATIONS, AND WITHOUT ANY REAL FORCING
EXPECT TODAY'S ACTIVITY TO REMAIN CONFINED TO THE HIGH TERRAIN.
TONIGHT, WITH A SOUTHEASTERLY LLJ, MOST CAMS SHOW SOME WEAK STORMS
OVER FAR SOUTHEAST MT, WHICH MAY LINGER TO SUNRISE TOMORROW.
TODAY'S STORMS WILL BE CAPABLE OF PRODUCING HEAVY RAIN AND ERRATIC
GUSTS, BUT SHOULD REMAIN SUB-SEVERE W/ BULK SHEAR OF 20KTS OR
LESS.
WEDNESDAY LOOKS LIKE THE MOISTEST DAY OF THE WEEK W/ PWATS CLOSER
TO 1.5". ALSO, THERE IS A DISTINCT WAVE THAT IS EXPECTED TO EMERGE
FROM THE NORTHERN GREAT BASIN AND TRACK THRU THE REGION LATE
TOMORROW THROUGH TOMORROW NIGHT. AGAIN, SEVERE WX IS NOT EXPECTED
PER WEAK SHEAR, BUT VERY HEAVY RAIN AND ERRATIC WINDS (WET
MICROBURSTS POSSIBLE) ARE RISKS. STORM COVERAGE SHOULD BE GREATEST
NEAR MOUNTAINS & FOOTHILLS, AND STORM MOTION WILL BE SLOW, SO
HAVE ISSUED A FLOOD WATCH FOR POTENTIAL FLASH FLOODING ACROSS THE
SW/S (ALONG AND SOUTH OF A LINE FROM LIVINGSTON TO COLUMBUS TO
LODGE GRASS). BURN SCARS SUCH AS ROBERTSON DRAW, EAST SIDE AND ELK
WILL BE PARTICULARLY SUSCEPTIBLE TO FLASH FLOODING W/ DEBRIS
FLOWS. TIMING OF THE WATCH IS FROM 1PM TO 2AM.
WET THUNDERSTORM ACTIVITY WILL CONTINUE THURSDAY BUT THE AIR MASS
WILL BEGIN TO TURN DRIER BEHIND THE EXITING SHORTWAVE. STILL A
RISK OF HEAVY RAIN BUT NOT TO THE EXTENT OF WEDNESDAY. WPC HAS
SOUTHERN PORTIONS OF THE REGION HIGHLIGHTED FOR A LOW RISK OF
EXCESSIVE RAIN EACH OF THE NEXT TWO DAYS. STAY ALERT IF YOU HAVE
OUTDOOR/RECREATION PLANS. TEMPS TOMORROW AND THURSDAY WILL REMAIN
SEASONABLE WITH HIGHS MOSTLY MID 80S TO LOWER 90S.
THE AIR MASS WILL TURN NOTABLY DRIER BY FRIDAY AS THE EXITING WAVE
SCOURS OUT THE DEEP MONSOONAL MOISTURE IN PLACE. THAT SAID, PWATS
WILL STILL BE NEAR TO SLIGHTLY ABOVE NORMAL, SO THERE REMAINS A
SLIGHT (10-20%) CHANCE OF HIGHER BASED T-STORMS EACH DAY THROUGH
THE FIRST PART OF NEXT WEEK. HOWEVER, THE MAIN STORY IS THE STRONG
RIDGE EXPECTED TO BRING HOTTER & DRIER CONDITIONS STARTING
FRIDAY. MIXED WEST WINDS LOOK TO BE BREEZY ON FRIDAY, WITH DEEP
MIXING EXPECTED TO PUSH TEMPS BACK TO TRIPLE DIGITS. ALONG WITH
HUMIDITIES IN THE TEENS, WOULD EXPECT FIRE CONCERNS TO BE ON THE
INCREASE AGAIN AFTER ABOUT OF WEEK OF ELEVATED RHS. TRIPLE DIGIT
HIGHS ARE LIKELY AGAIN SATURDAY, THOUGH WITH LESS WIND. THE
SUNDAY/MONDAY TIME PERIOD MAY SEE A BRIEF FLATTENING OF THE RIDGE
AND POSSIBLE WEAK COLD FRONT, THUS SOMETHING TO MONITOR WITH
REGARD TO FIRE WEATHER/WIND. OVERALL, THE LONGWAVE PATTERN THRU
NEXT WEEK FAVORS ABOVE NORMAL HEIGHTS AND TEMPERATURES.
FOR THOSE FOLLOWING THE JULY 25TH DRAMA, THE ODD (AND MEANINGLESS)
FACT THAT THE BILLINGS AIRPORT HAS NEVER REACHED 100F ON THIS DATE
GOING BACK TO 1934, CONFIDENCE IS GROWING THAT THE SITE WILL
FINALLY REACH TRIPLE DIGITS. CURRENT FORECAST FOR BILLINGS IS
103F, WHICH WOULD EASILY BREAK THE OLD RECORD OF 98F SET ON FOUR
OCCASIONS. THE WILDCARD IS SMOKE AND HIGH CLOUD COVER, WHICH COULD
HOLD TEMPS BACK SLIGHTLY. STAY TUNED.
JKL
AVIATION
SHOWERS AND THUNDERSTORMS INCREASE THIS AFTERNOON AND EVENING,
MOVING WEST TO EAST. THE HIGHEST CHANCE (30-50%) IS OVER THE
MOUNTAINS AND ALONG THE MT/WY BORDER. LOCALIZED VISIBILITY
REDUCTIONS DUE POCKETS OF HEAVY RAIN ARE POSSIBLE UNDER ANY
SHOWERS OR STORMS. WILDFIRE SMOKE FROM THE PACIFIC NW MAY PRODUCE
SLANT RANGE VISIBILITY REDUCTIONS AT TIMES, BUT SURFACE
VISIBILITY REDUCTIONS ARE NOT EXPECTED. ARCHER
PRELIMINARY POINT TEMP/POPS
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 065/091 067/092 066/102 068/102 069/100 067/096 068/097
11/U 44/T 11/G 21/G 21/U 21/U 20/U
LVM 057/089 057/091 058/098 059/098 059/096 057/095 058/095
14/T 64/T 10/U 11/N 22/T 22/T 22/T
HDN 063/093 064/092 062/102 064/104 066/102 066/099 067/099
21/U 44/T 00/G 21/G 20/G 11/U 21/U
MLS 064/092 066/093 066/104 069/105 072/102 069/100 070/100
10/U 11/B 00/G 10/G 21/G 11/U 21/U
4BQ 064/090 065/089 065/101 068/103 070/101 070/099 070/099
40/U 54/T 10/G 11/G 21/G 11/U 32/T
BHK 059/088 060/091 062/102 066/105 068/102 065/099 066/099
10/U 11/B 10/G 11/G 11/G 11/U 21/U
SHR 060/089 061/086 059/100 063/100 065/099 064/095 064/096
34/T 67/T 10/U 01/U 11/U 12/T 22/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...FLOOD WATCH IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR ZONES 56-64>67-138-139-169>171.
WY...FLOOD WATCH IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR ZONES 198-199.
WEATHER.GOV/BILLINGS
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